30 Hidden Reasons You've Gained Weight

By Christina Stiehl

If you're eating healthy, working out on the regular and still be packing on the pounds, these underlying health issues and common lifestyle mistakes could be the culprit.

Most people understand that losing weight requires a delicate mix of eating the proper foods, exercising regularly, and drinking enough water. But what if you're doing all the right things and still notice the scale creep up? There could be some hidden culprits to your sudden weight gain that you may not have considered.

Even "healthy" foods and habits can lead to weight gain. And there are some physiological issues beyond your control that could also contribute to an expanding waistline. Although this list, from the researchers at Eat This, Not That, provides insight on what's possibly going on, be sure to consult your doctor if you think it's something more serious or persistent. And if you're stuck in a weight-loss plateau, don't miss our essential report: 50 Best-Ever Weight-Loss Tips.

1

You're not tracking portion sizes

Even healthy food can cause weight gain if you're not careful. All food has calories, and if you aren't measuring out your meals and snacks, you could easily go over your daily recommended intake. For example, almonds are a healthy snack, but one serving is just ¼ of a cup and is 162 calories. Be sure you're really tracking your portions by using measuring cups and food scales. For more tips, check out our 18 Easy Ways to Control Your Portion Sizes.

2

You haven't changed up your workout

Diet and exercise go hand-in-hand for weight loss, but you have to constantly challenge yourself to see your results. Your body is extremely adaptable, so if you're doing the same 20-minute run every day for months, your body starts to get used to this level of activity. Shock your system by mixing it up; throw in some HIIT circuits, try a cycling class, or take up swimming. Make sure your workouts are varied each day to prevent boredom (and a plateau).

3

You are eating too much sugar

Like a drug, eating sugar gets you hooked on the sweet stuff and keeps you craving more, according to new research in Zero Sugar Diet. It makes you fat, tired, and cranky. In fact, sugar is the culprit behind America's obesity epidemic and related diseases such as type 2 diabetes and hypertension. And it's in everything. Even if you make an effort to avoid sweets and sugary beverages, it could still be lurking in your favorite condiment or protein bar. Just look at these 30 Foods with More Sugar Than a Donut. Be sure to check your labels for not just grams of sugar, but also ingredients: fructose, sucralose, high fructose corn syrup, and dextrose are all common names for added sugars. Aim to eat no more than 6 teaspoons (about 25 grams) of added sugar a day.

4

You're not sleeping enough

You know getting enough Zzzs is essential for good health. Ideally, people would be getting 7-8 hours of shut-eye a night -- any less, and you're opening yourself up to junk food cravings, fatigue, and yes, weight gain. Although 8 hours of sleep a night isn't plausible for everyone, try to hack your sleep cycle by going to bed and waking up at the same time every day, even on the weekends. And if you can fit it in during the day, take a quick 20-minute power nap.

5

Or you're sleeping too much

On the flip side, there is such a thing as too much sleep. Aside from sleeping in too much to make it to the gym or make a healthy breakfast, your body truly does not function at its best if you sleep too long. A study published in the Social Science & Medicine journal found that people who overslept were found to be more obese, and at risk for diseases like diabetes and hypertension. So take a cue from Goldilocks and make sure your hours of sleep are juuuuussst right.

6

You have a thyroid issue

Although thyroid issues aren't as common as people think, hypothyroidism, or an underactive thyroid, can contribute to weight gain. Since your thyroid controls your metabolism, when it's running slowly, that can lead to unwanted weight gain. If you are noticing weight gain along with fatigue, constipation, sensitivity to the cold or puffiness in your face, be sure to see a doctor and get your thyroid tested.

7

You're getting older

Gray hair and aching joints aren't the only things you have to look forward to as you age; weight gain is almost a guarantee if you're not careful. Your metabolism slows down as you get older, and your body just isn't as capable of the intense workouts you used to be able to do in your youth.

8

You have too much stress

It seems like everyone is stressed these days. You might be so bogged down from chronic stress thanks to your career, family, and personal life, and not even realize it. But too much stress, especially for long periods of time, causes your body to release the stress hormone cortisol. Although it's necessary to regulate blood pressure and fluid balance, your body ends up storing it as belly fat. Stress isn't something that magically disappears, but you can help get it under control through exercise, meditation, or eating the right foods: check out these 5 Foods That Fight Stress.

9

You reward yourself after a workout

You may feel like you've earned that burger and fries after a particularly strenuous workout. After all, you sweated for an hour and must have burned, what, hundreds of calories? Not quite. People tend to overestimate just how many calories they burn during a workout. In reality, it ends up being more like a couple hundred calories, tops. Compare that to an average burger-and-fries meal, which can be up to 1,000 calories easily. Since weight-loss is 80% diet and 20% exercise, don't treat training days any differently than you would any other day. Refuel with something better, like these 23 Best Protein Shake Recipes.

10

You have an insulin resistance

After you eat, your body releases insulin to regulate your blood sugar levels. Insulin helps your fat, muscle, and liver cells absorb the glucose, so the more sugars and simple carbohydrates you eat, the more insulin your body needs. However, if you're insulin resistant, your cells won't respond to the insulin that's being released and your blood sugar levels stay high, resulting in weight gain. If you've noticed unexplained weight gain, especially in your belly, be sure to visit a doctor to get tested. You can regulate insulin resistance with certain medication and a low-carbohydrate diet.

11

Your gut bacteria are off

Although the complexities of your gut health are still being figured out, scientists believe that the makeup of your gut microbiome could influence your weight. Research from the Weizmann Institute of Science found a correlation between gut bacteria and yo-yo dieters. Make sure you're feeding your gut properly with these 23 Best & Worst Probiotic Foods.

12

You have an unknown food intolerance

Some food allergies are obvious and majorly debilitating for people: peanuts and shellfish, for example. But a lot of people have low-level food intolerances, such as to gluten or dairy. Although these foods won't send you into anaphylactic shock, they do create inflammation in the body. Inflammation is necessary for the body to fight off disease and injury, but chronic inflammation can lead to a leaky gut, extra cortisol, and yes, weight gain. If you notice you're feeling particularly fatigued and packing on the pounds, try an elimination diet where you eliminate particular food groups (dairy, gluten, added sugars) for 30 days, and monitor how you feel. Once you add each food back into your diet, notice if it creates any unpleasant symptoms. If so, be sure to eliminate or at least limit those foods in an effort to stave off inflammation, and eat more of our 30 Best Anti-Inflammatory Foods.

13

You're eating diet foods

You may think you're doing yourself a favor by picking up a snack that's labeled low-fat or sugar-free. After all, the bad stuff must be taken out if it's diet, right? Not exactly. Diet foods are still highly processed and laced with extra chemicals your body certainly doesn't need. Plus, low-fat is usually code for extra sugar, and sugar-free means the sugar was replaced with artificial sweeteners. Your best bet is to stick whole foods found in nature, especially if you're trying to lose weight.

14

Your family is overweight

Even if you eat well and are super active, some people are just genetically predisposed to gain weight. If your family is overweight, especially if they started gaining suddenly in their 20s or 30s, it could be a sign that you're destined to pack on the pounds as well. Fight back against your genes as much as possible through a clean diet and regular exercise.

15

You watch too much TV

It's pretty obvious that extra time in front of the small screen instead of, say, at the gym is going to cause you to gain weight. But getting lost in a Netflix binge can make you pack on the pounds in other ways, too. It's easier to mindlessly eat in front of the TV and lose track of how much you're chowing down. Plus, the artificial light messes with your sleep cycle, causing you to lose out on those precious Zzzs necessary for maintaining a healthy weight.

16

You rely on artificial sweeteners

Sipping on diet soda or sprinkling a no-calorie sweetener into your coffee may seem like a smart way to save calories. After all, calories = weight gain, right? Not exactly. Like sugar, researchers have found that artificial sweeteners also lead to weight gain. A study published in the Yale Journal of Biology and Medicine found that artificial sweeteners led to more sugar cravings/ Another study in the Journal of American Geriatric Society, which followed a group of people aged 65 and older for 20 years, found that people who drank diet soda were more likely to be obese, especially in their bellies. Your best bet is to limit sugar consumption and stay away from the fake stuff; water, unsweetened tea, and black coffee are your friends.

17

You're retaining water

Not all weight gain is fat. In fact, if you've been eating a particularly high-sodium diet, it could just be extra water weight. affecting the scale. Although drinking more water seems counter-intuitive, it actually helps your body flush out that extra water weight and de-puff. Staying away from extra carbs and working out can also help you drop those extra pounds.

18

You are taking a new prescription

Unfortunately, weight gain is a common side effect for a number of prescription medications. It's especially common in psychotropic drugs used to treat mental illness such as bipolar disorder and schizophrenia. Antidepressants and anti-seizure medications can also lead to weight gain, as can beta-blockers used to treat blood pressure. Be sure to talk to your doctor if you notice the scale creep up after getting started on a new medication.

19

You're depressed

Depression is already a debilitating disease. Add weight gain to the mix, and it can make life even worse. In a study published in the American Journal of Public Health, people who experienced depression symptoms (sadness, loneliness) gained weight faster than those who didn't. On top of antidepressants causing weight gain, people who are depressed may tend to reach for high-calorie comfort foods in an effort to feel better or have lost the motivation to exercise. If you're experiencing symptoms of depression, make sure you tell your doctor, and let him or her know that you prefer to be put on a medication that won't cause weight gain.

20

You're misreading food labels

Most people focus on just the calorie and maybe fat content of food labels, but the nutritional guide is much more nuanced than that. First of all, serving sizes are key; a box of whole grain cereal may only list 80 calories per serving, but if that serving is ¼ of a cup, you're bound to dump much more than that into your morning bowl. Also, be sure to pay attention to the ingredients list. Anything more than a few familiar ingredients should be avoided, especially if the first three ingredients is sugar, or a sugar variation (dextrose, corn syrup, high fructose corn syrup).

21

You're too restrictive

How's this for a paradox: Sometimes not eating enough can actually lead to weight gain. When you deprive yourself of the calories and nutrients your body needs to function, it actually slows down your metabolism. And if you skip a meal in an effort to slim down, you'll likely sabotage yourself by being too hungry and overeating at the next possible opportunity. Although everyone is different, sticking to around 1,200-1,500 calories (depending on activity level) is ideal for women looking to lose weight in a healthy, sustainable way.

22

You're not lifting weights

Slogging away on the treadmill may seem like torture, and it could all be for nothing. Sure, cardio workouts are important for overall health and can help you shed pounds, but it's not enough to see long-term results. When researchers at Penn State put dieters into three groups: exercise, aerobic exercise only, and aerobic exercise with weight training, the people who lifted weights lost more fat than the other groups. When you lift weights you build muscle, which burns fat even at a resting heart rate. Be sure to incorporate weight training into your workouts to see optimal results.

23

Your hormones are unbalanced

Although men and women have a different hormonal makeup, the careful balance of each is essential for maintaining a healthy weight. If women have too much estrogen, they can end up having an insulin resistance and store more fat. For men, too-low testosterone can slow down your metabolism. If you think your hormones are the problem, be sure to visit your doctor to get your levels tested.

24

You're not eating enough fat

The idea that fat makes you fat is an ‘80s-era myth that should be tossed out with the thigh master. It turns out sugar is more detrimental to your health than fat, especially when it comes to heart health. A study published in the journal Progress in Cardiovascular Diseases found that excess sugar consumption was a bigger factor for coronary heart disease than eating saturated fat. Plus, healthy fats like the ones found in nuts, avocados, and fatty fish leave you feeling fuller, longer. And to discover even more stomach-slimming tips, check out these 55 Best Ways to Boost Your Metabolism!

25

You're losing muscle mass

The old adage of "muscle weighs more than fat" is misleading. First of all, a pound of muscle weighs the same as a pound of fat. But more than that, building muscle is actually necessary for weight loss. Having more muscle mass actually speeds up your metabolism, leading to more fat burning and thus weight loss. As you get older, your lean muscle mass starts to decline especially after age 40. And if you've been ignoring the weight room, then you're particularly at risk for losing muscle. Be sure to keep lifting weights, and recover with a protein shake.

26

You're eating meat with hormones

Factory-farmed livestock is usually pumped full of hormones to make them bigger to produce the most meat possible. So it would make sense that these additives, which are still in the meat when we eat them, would do the same for humans. Choose meat and poultry that aren't treated with hormones, and better yet find brands that are also antibiotic-free.

27

You're not mindfully eating

Do you scarf down your lunch while scrolling through your phone or enjoy dinner while binge watching the latest series on Netflix? It's all too common nowadays, but it can cause you to overeat. British researchers found that people who ate in front of the TV consumed up to 25% more calories than those who didn't. Eating should be pleasurable, and mindfully eating your meal while paying attention to the flavor and texture will help you not only enjoy it more but pay attention to your body's fullness signals.

28

You're eating too much protein

Sure, protein can help you lose weight, especially these 29 Best-Ever Proteins for Weight Loss. But just like the other macronutrients, you can have too much of a good thing. When people hear that protein can help you lose weight, they tend to go overboard, stocking up on protein shakes, bars, and big portions of meat at every meal. In reality, the average 140-pound woman who works out 3-5 days a week should be eating around 50 grams a day, while an 180-pound man with the same activity level would need about 80 grams. Any more and your body is likely to store it as fat -- not good!

29

You aren't getting enough micronutrients

Sure, maybe you're getting a good mix of proteins, fats, and carbs, but what about vitamins and minerals? If you're not eating enough magnesium, iron or vitamin D, it could slow down your metabolism. Make sure you're taking a supplement like a multivitamin and eating a diet rich in colorful veggies to get all the micronutrients you could be missing.

30

You've lost a lot of weight in the past

It's true the hardest part of losing weight is keeping it off. So if you've lost a lot of weight in the past and are noticing it starting to creep back up, there could be a scientific reason why. In a study published in the journal Obesity, researchers followed 14 former contestants from the TV show The Biggest Loser and found they burned much fewer calories than other people would at their size. And most of them gained back either much or all of the weight they lost. Scientists believe losing that much weight, especially in a short amount of time, significantly slows down your metabolism.